TRPV4 Initiates Ventilator Induced Lung Injury

TRPV4 引发呼吸机引起的肺损伤

• 批准号: 7653156
• 负责人: JAMES Courtney PARKER
• 金额: $ 35.52万
• 依托单位: UNIVERSITY OF SOUTH ALABAMA
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-07-01 至 2011-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7653156
• 关键词: Acute Lung Injury; Adult Respiratory Distress Syndrome; Aftercare; Agonist; Alveolar; Alveolar Macrophages; Blood Coagulation Disorders; Blood capillaries; Breathing; Calcium; Cations; Cells; Clinical Research; Clinical Trials; Coagulation Process; Coculture Techniques; Cyclic AMP-Dependent Protein Kinases; Data; Endothelial Cells; Endothelium; Environmental air flow; Epithelial; Epithelial Cells; Epithelium; F2R gene; Fluorescence Microscopy; Genotype; Human; Infusion procedures; Intervention; Ion Channel; Laboratories; Link; Lung; Measures; Mechanical ventilation; Mechanics; Mediating; Mus; Neurons; PAR-2 Receptor; Patients; Peptide Hydrolases; Peptides; Permeability; Phorbol; Phorbols; Plasma; Plasma Proteins; Plasminogen Activator Inhibitor 1; Protein C; Proteinase-Activated Receptors; Pulmonary Edema; Reporting; Research; Rest; Secondary to; Sepsis; Stretching; Testing; Thrombin; Tidal Volume; Trauma; Trypsin; Vanilloid; Vascular Permeabilities; Ventilator-induced lung injury; activated Protein C; capillary; electric impedance; in vivo; inhibitor/antagonist; lung injury; macrophage; monolayer; mortality; patch clamp; pressure; prevent; receptor; response

After some 40 years of research and numerous failed clinical trials, only two interventions have been shown to significantly reduce the high mortality rate of the acute respiratory distress syndrome (ARDS), a reduction of tidal volume during mechanical ventilation (22%), and infusion of activated protein C (19%). These clinical studies indicate that coagulation activation renders the lung exquisitelv sensitive to stretch because the injurious lung distention producing a 22% increase in ARDS fatalities is half that in resting tidal breathing. We recentty reported that experimental Ventilator Induced Lung Injury was prevented in mice by deletion of the calcium-permeable stretch-activated transient receptor potential vanilloid-4 (TRPV4) ion channel. Recent studies indicate that the proteinase activated receptor-2 (PAR2) associates with the TRPV4 channel in neurons and greatly amplifies the TRPV4 induced calcium increase. We show (Preliminary Data) that lung epithelial cell monolayers co-cultured with alveolar macrophages activated with trypsin (PAR2), thrombin (PAR1, 3, 4) or the TRPV4 agonist, 4alpha-phoroot 12,13--didecanoate (4a-PDD) given separately actually decreased monolayer permeability, but that pre-treatment with either trypsin or thrombin followed by 4a-PDD produced a sustained permeability increase. We Hvpothesize: that coagulation induced proteases and TRPV4 induced alveolar macrophage release of proteases that activate PAR2 and PAR1, 3, and 4 which then amplify the mechanogated TRPV4 response in epithelial and endothelial cells sufficiently to cause increased lung vascular permeability. We propose these Specific Aims: 1) Test the hypotheses that: PAR1 and PAR2 activation peptides followed by 4a-PDD amplify the TRPV4 mediated calcium influx in alveolar macrophages and alveolar epithelial cells measured using whole cell patch clamp and fluorescence microscopy; and that the PAR amplification is reduced by inhibitors of PLC~, PKA, and PKC. 2) Test the hypothesis that PAR1 and PAR2 activation peptides followed by 4a-PDD increases alveolar epithelial monolayer permeability using electric cell-substrate impedance sensing, and that lung PAR1 and PAR2 activation peptidesincrease lung vascular permeability in TRPV4+/+ mice ventilated with high airway pressures but not in TRPV4-/- mice, or either genotype ventilated with low airway pressures

经过大约40年的研究和无数失败的临床试验，只有两种干预措施被证实是有效的。 能显著降低急性呼吸窘迫综合征的高死亡率 （ARDS），机械通气期间潮气量减少（22%），输注活化的 蛋白C（19%）。这些临床研究表明，凝血激活使肺 对拉伸非常敏感，因为有害的肺膨胀会增加22%， ARDS死亡率是静息潮式呼吸的一半。我们最近报道，实验性呼吸机 通过删除钙渗透性牵张激活蛋白来预防小鼠诱导性肺损伤 瞬时受体电位香草酸-4（TRPV 4）离子通道。最近的研究表明， 蛋白酶激活受体-2（PAR 2）与神经元中的TRPV 4通道相关， 增强TRPV 4诱导的钙增加。我们显示（初步数据）肺上皮细胞 与用胰蛋白酶（PAR 2），凝血酶（PAR 1，3， 4)或TRPV 4激动剂，4 α-磷酸根12，13--双癸酸酯（4a-PDD），实际上单独给药 降低单层渗透性，但用胰蛋白酶或凝血酶预处理， 4a-PDD产生持续的渗透性增加。我们认为：凝血引起的 蛋白酶和TRPV 4诱导肺泡巨噬细胞释放激活PAR 2的蛋白酶 和PAR 1、3和4，然后放大上皮细胞中的机械化TRPV 4应答， 内皮细胞足以引起肺血管通透性增加。我们建议这些 具体目的：1）检验以下假设：PAR 1和PAR 2激活肽后是4a-PDD 增强肺泡巨噬细胞和肺泡上皮细胞中TRPV 4介导的钙内流 使用全细胞膜片钳和荧光显微镜测量;并且PAR扩增 PLC、PKA和PKC的抑制剂可使其降低。2)检验假设PAR 1和PAR 2 活化肽后4a-PDD增加肺泡上皮单层通透性， 电细胞基质阻抗传感，肺PAR 1和PAR 2激活肽增加 TRPV 4 +/+小鼠在高气道压力下通气时的肺血管通透性， TRPV 4-/-小鼠或任一基因型低气道压通气